1. Field of the Invention
The invention relates generally to emergency unit lighting fixtures and particularly to lamp assemblies usable with such fixtures and which are both adjustable as to the direction in which light is directed and as to beam width.
2. Description of the Prior Art
Emergency unit lighting fixtures have long been known in the art and have long been required by code for illumination of egress pathways, doorways and the like for facilitating evacuation of a building, typically a commercial or industrial space within a building, during emergency conditions which usually are accompanied by failure of mains power supply resulting in loss of usual illumination sources. Emergency unit fixtures typically take the form of a housing within which an emergency power supply, usually batteries, and circuitry are disposed for driving one or more lamps mounted to the exterior of the housing. In most typical unit fixtures, a pair of lamps are mounted to the top of a unit housing with each lamp being directed forwardly and to the side of that side of the housing on which the lamp is mounted. Such unit figures are often referred to as "frog eyes" and typically do not include a "legend" as do exit signs, thereby allowing use of unit fixtures in locations inappropriate for an exit sign. Further, a unit fixture is intended to provide a usable amount of light, such as along a hallway or the like, to enable a person evacuating a space to follow a preferred pathway out of that space. As disclosed by Edstrom in U.S. Pat. No. 4,422,069, the external lamps of such unit fixtures provide illumination incident on desired surfaces so that a person evacuating the space within which an emergency exists will be able to see a pathway or an exit inter alia. Typical unit fixtures are disclosed by Heffner et al in U.S. Pat. No. 4,218,725.
Emergency unit fixtures have primarily found use in commercial environments which have previously included industrial environments. However, in spite of prior usage of this type of lighting fixture in industrial environments, a need has continued to exist for improved emergency unit fixtures mountable virtually anywhere within an industrial environment and lamped with illumination sources having desirable characteristics. Further, a need exists in the art for emergency unit fixtures useful in industrial environments whereby light from appropriate lamping can be directed to a particular location within a wide range of possible locations within the industrial space proximate to the unit fixture. Still further, need has existed for control of a light beam emanating from lamping of an emergency unit fixture so that the beam can be adjusted between narrow and wide beam conformation. The present invention provides emergency unit fixtures capable of withstanding the abuse typically encountered in industrial environments, the unit fixtures being mountable to a variety of structure within the industrial environment and further being comprised of at least one lamp assembly movable relative to a housing of the fixture in a swiveling motion and further being movable along an internal track within the assembly to allow light emanating from the lamp assembly to be directed as desired to illuminate a particular area chosen for criticality in evacuation of the industrial space or for some reason of importance. The illuminating beam provided by the lamp assemblies of the invention can be adjusted between narrow beam and wide beam light distributions to provide flexibility in operation of the emergency unit fixtures so configured.